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A fair number of research groups are working to develop a technology platform for effective and rapid nerve repair. One of the many parallel lines of research involves the use of Schwann cells, a part of the supporting infrastructure for the nervous system. As for much of the field of regenerative medicine, work has progressed through stages of increasing sophistication: learning how to isolate and culture useful cells, and then introducing those cells into damaged areas, or incorporating them into existing therapies.

Here is a very readable review paper on this topic, entitled Peripheral Nerve Repair with Cultured Schwann Cells: Getting Closer to the Clinics:

Peripheral nerve injuries are a frequent and disabling condition, which affects 13 to 23 per 100,000 persons each year. Severe cases, with structural disruption of the nerve, are associated with poor functional recovery. The experimental treatment using nerve grafts to replace damaged or shortened axons is limited by technical difficulties, invasiveness, and mediocre results. Other therapeutic choices include the adjunctive application of cultured Schwann cells and nerve conduits to guide axonal growth. The bone marrow is a rich source of mesenchymal cells, which can be differentiated in vitro into Schwann cells and subsequently engrafted into the damaged nerve.

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Cell-based therapy associated with scaffolds is a promising branch of regenerative medicine. ... The idea of using nerve conduits filled with bone-marrow mesenchymal cells may be an attractive alternative to more aggressive therapies. If successful, the treatment may lead to functional improvement, avoiding the hurdles of additional surgeries and use of immunosuppressive drugs. A hypothetical scenario would be a patient with a traumatic limb injury, including extensive and severe damage of a motor nerve, resulting in acute disability. There would be a nerve gap, precluding any attempt of direct nerve suture. The use of a nerve conduit filled with allogeneic bone marrow-derived MSCs would be proposed, as an alternative to the standard autologous nerve graft implant. The acute nature of the condition would require a readily available source of cells, and since MSCs are immunoprivileged, indicating poor alloimmune response and therefore delayed rejection, allogeneic sources would be ideal. The cells would be already isolated from donated bone marrow, expanded in culture without further manipulation, tested for safety and quality, cryopreserved and ready for clinical use. The necessary amount of cells would then be thawed and inserted into biodegradable nerve conduits, readily implanted between nerve stumps during microsurgery.

The therapy would require no immunosuppression and sequential functional and electromyographical evaluations would determine the outcomes. Expected results would be axonal repair, remyelination, and progressive functional improvement, either through differentiation of the transplanted into Schwann-like cells or, most probably, through paracrine effects of the bone-marrow-derived MSCs on the proximal axonal stump and remaining endogenous Schwann cells, stimulating regeneration.

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Schwann cell cultures have demonstrated favorable results in the experimental setting; however, the ideal source of cells has not yet been established. Bone-marrow-derived mesenchymal cells present encouraging results and may become the ideal cell for clinical translation. These cells have been exhaustively investigated during the last two decades and approved for use in numerous clinical trials

It is interesting to note that there are areas of stem cell medicine in which cell transplants from other people are just as useful as autologous cells obtained from the patient, this being one of them. So there is less of a motivation in this line of work to develop the techniques of culturing patient cells versus the long-established use of donor tissue.